'Thunder' in Saudi desert as major military drill ends

Smoke billows following an aerial bombardment during the Northern Thunder military exercises in Hafr al-Batin, 500 kilometres north-east of the Saudi Capital Riyadh on March 10, 2016 Armed forces from 20 countries have begun manoeuvres in northeastern Saudi Arabia that the official Saudi Press Agency described as one of the world's biggest military exercises. Troops from Pakistan, Malaysia, Turkey, Egypt, Morocco, Jordan and Sudan are among those participating in the "Thunder of the North" exercise, which involves ground, air and naval forces, SPA reported. (AFP Photo/Fayez Nureldine)

King Khalid Military City (Saudi Arabia) (AFP) - Warplanes roared overhead, tanks rumbled across the desert and smoke filled the sky Thursday for the final day of what Saudi Arabia billed as the region's biggest-ever military exercises.

The 12-day "Northern Thunder" manoeuvres in the kingdom's northeast included 20 nations from the Middle East, Africa and Asia, Saudi officials said.

Saudi Arabia's King Salman was joined by several foreign leaders for the final day of the exercise, which came as Riyadh vies to assert its leadership in the region.

As the dignitaries watched from a pavilion, Apache gunships fired rockets with a bone-shaking blast. Smoke rose from targets on the ground and commandos rappelled from helicopters.

Fighter jets streaked through the sky releasing orange flares, artillery shells whistled through the air and heavy machinegun fire boomed from across the drill site, which stretched for dozens of kilometres (miles).

The exercises took place near Hafr al-Batin city, close to the Kuwaiti and Iraq borders.

Saudi Arabia's chief of staff, General Abdulrahman al-Bunyan, commanded the exercise and called it "the largest Arab and Islamic military gathering" in the region.

Riyadh has adopted a more assertive foreign policy since Salman took the throne early last year following the death of his half-brother king Abdullah.

It leads a coalition fighting rebels in Yemen, participates in US-led air strikes against the Islamic State group and has offered to send special forces to fight IS in Syria.

"Northern Thunder" also took place after tensions escalated between Sunni-dominated Saudi Arabia and its regional Shiite rival Iran, which back opposing sides in Syria and Yemen.

Riyadh cut diplomatic ties with Tehran earlier this year after mobs ransacked Saudi diplomatic missions in Iran following the execution of a prominent Saudi Shiite cleric.

Saudi Brigadier General Ahmed al-Assiri told reporters this week the exercises were preparation to tackle the region's "terrorist menace" and were not directed against Iran.

Assiri said the manoeuvres are distinct from a 35-nation coalition to fight "terrorism" which Saudi Arabia announced in December.

Officials have said the new coalition would gather in the kingdom this month for its first publicly announced meeting.

Authorities released no figures for the number of troops taking part from each country in Northern Thunder.